Such a device and method are known from the publication DE 20 2007 006 521. This publication shows a device for filling a drinking glass with separated liquid layers. The device comprises one injector which is connected via three channels to three liquid reservoirs. The injector is provided with three separated feed conduits, each with its own outflow opening. Each individual feed conduit is connected to only one liquid reservoir. The orientation of the outflow opening for the liquid which flows first into the drinking glass is directed downward, i.e. it is directed during use toward the bottom of the holder. The outflow openings for the liquids injected after the first liquid are directed toward the side walls of the drinking glass so that these liquids flow downward from the side wall. The effect hereof is that the flow of the liquid along the side wall is slowed down. During use the injector is first moved downward in the holder. The drinking glass is then filled with the first liquid. As the liquid level in the drinking glass rises, the injector moves upward and at a chosen moment there is a changeover to a different liquid and outflow opening. A drinking glass is thus filled with a layered liquid composition by means of the device. During filling the moving means set the height of the injector, and so the distance between the injector and the holder, for each layer.
A drawback of such a device is the complicated design of the injector through which different conduits with specific outflow openings are provided. Each conduit has its own pump here, this being a drawback in respect of the maintenance and vulnerability of the device. Another problem is that the inflow of liquids along the side walls does not slow down the flow sufficiently, whereby an optimal separation of layers is not obtained.
It is noted that there are a number of reasons why an optimal boundary layer, i.e. a sharp boundary layer, is desirable. A first reason is the visual effect of the layered drink in the glass. When the different liquids of the layered drink each have for instance a different colour, a visual effect can be achieved in that each layer as it were forms a colour with sharp contrasts, for instance similar to colour combinations of national flags, or corresponding to a company logo. If separating layers are not sufficiently sharp, the obtained layered drink will appear indistinct or untidy, which is undesirable. A second reason is the taste effect which occurs when the different liquids of a layered drink mix with each other. Owing to a sharp boundary layer between the different liquids (e.g. alcoholic drinks) of the obtained drink this taste effect will only occur in the mouth of a person consuming the drink. A sharp boundary layer between the liquids thus achieves that the user experiences this taste effect optimally during consumption.